49. (a) Find the electric field at the location of q in Figure 18.54, given that q = qb= q = -4.2C, and the distance between each charge on this equilateral triangle is d = 27.1m. (Enter the magnitude answer with proper units and in calculator notation: 3.00X108 m/s entered as 3.00E8*m/s.) (b) What is the force on qa? (Enter the magnitude answer with proper units and in calculator notation: 3.00X108 m/s entered as 3.00E8*m/s.) O q= qa O 195 Figure 18-54. Answer Electric Field: Answer Force on